## subtract() function  
List the keys in `minuend` that are not in `subtrahend`.

A key is only considered if it is both 1) an own-property (o.hasOwnProperty(k)) of the object, and 2) has a value that is not undefined. This is to match JSON semantics, where JSON object serialization drops keys with undefined values.

**Signature:**
```typescript
export declare function subtract(minuend: {
    [index: string]: any;
}, subtrahend: {
    [index: string]: any;
}): string[];
```

## Parameters
| Parameter | Type | Description |
| --- | --- | --- |
| minuend | { [index: string]: any; } | Object of interest |
| subtrahend | { [index: string]: any; } | Object of comparison |

**Returns:**

string[]  
Array of keys that are in `minuend` but not in `subtrahend`.